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Emerging technologies based on polymeric materials are progressively developed in order to preserve and consolidate cultural heritage artifacts. In this study, we aimed to obtain a hybrid polymer reliant on two types of thermosets that undergo irreversible crosslinking via ionizing radiation-induced polymerization, the polymer's structure and characteristics being tailored using specific dose rates, doses, linear energy transfer and monomers ratio, in order to achieve the established performance requirements. Here, we demonstrate a covalently bonded 3D hybrid diepoxy-triacrylic polymer that is chemically and dimensionally stable, intending to use it as a consolidant of highly degraded wooden artifacts in order to mitigate oxygen inhibition from radical chain reactions, to increase chemical and thermal stability, as well as to obtain a stiffer consolidated artifact, therefore more resistant to deformation. Various types of analytical techniques such as Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy, Mass Spectrometry or Thermal analysis were performed in order to support our strategy and predictions regarding the synergistic effect given by gamma irradiation-driven crosslinking through simultaneous cationic and radical chain growth polymerization reaction mechanisms. We achieved a homogenous polymeric formulation and wood-polymer composite materials with high modulus of elasticity, therefore providing up to a twofold increase in Young's modulus in the consolidated wood, a good chemical resistance to various solvents and outstanding thermal resistance up to 381°C. Consequently, the consolidation methodology, as well as mechanical testing, analytical and morphological characterization of the resulted composite will be discussed. Apart from consolidating cultural heritage wooden artifacts, this synthetic route and impregnation methodology provide opportunities for wood-polymer composites in a wealth of applications as reinforced wood-based materials. [ABSTRACT FROM AUTHOR]

In the present work, poly(acrylamide-acrylic acid)-SiO2, p(AM-AA)-SiO2, was made with a template polymerization technique induced by gamma irradiation as an initiator under an irradiation dose of 60.00 kGy. The produced hybrid polymer was investigated using different techniques such as scanning electron microscope (SEM), Fourier-transform infrared (FT-IR), thermogravimetric analysis (TGA), and X-ray fluorescence (XRF) and was applied for the separation of Y(III) and Sr(II) using column chromatography resulting in an acceptable separation. The results exhibited that the percentage of adsorption of Y(III) in the binary system increased with increasing pH value with a slight uptake percentage of Sr(II) ions in the batch technique. The highest removal percentage of Y(III) was about 90.00% with a low amount of Sr(II) and was achieved at pH 4.00 in batch technique with specific values of the distribution coefficient (Kd) and separation factor (SF). The loaded percentages of Y(III) and Sr(II) on the packed column were 95.50 and 40%, respectively, at the best conditions. The results illustrated that the recovery Y(III) and Sr(III) from the packed column were 98.97 and 96.65%, respectively, using 25% ethanol followed by 0.001 M HNO3. The hybrid polymer could be regenerated and achieved, and the results are relevant that there is no change in adsorption ability of p(AM-AA)-SiO2 after three times of use. The results recommended that the p(AM-AA)-SiO2 is effective for the separation and purification of Y(III) from Sr(II) ions. [ABSTRACT FROM AUTHOR]

Abstract We demonstrate the fabrication of microoptical elements made from hybrid polymers using two-photon polymerization. To overcome the throughput limitations of two-photon polymerization we use galvanometric mirrors and propose a hatching strategy for rotationally symmetric objects which allows a significant process acceleration to tolerable fabrication times while preserving the surface accuracy of the fabricated elements. Using this strategy and optimized processing parameters we demonstrate the fabrication of an aspheric microlens for diffraction limited focusing which could be fabricated in less than 1.5 min. Thorough topographic characterization with atomic force microscopy and laser scanning microscopy reveal excellent agreement of the fabricated surfaces with the theoretical design with a surface accuracy below 100 nm. Our approach enables the generation of arrays of custom shaped lenses and large arrangements of freeform microoptical elements in a few hours. Highlgihts • Two-Photon Polymerization for arbitrarily shaped microoptical elements • Surface deviations below 200 nm with additive manufacturing of optical components • Custom-shaped arrays and arrangements of refractive microoptical elements • Fast and accurate fabrication strategy for additive manufacturing of optical components [ABSTRACT FROM AUTHOR]

We report on cellular adhesion of human primary fibroblasts on scaffolds fabricated by laser-induced two-photon polymerization using 515 nm femtosecond pulses. The scaffolds are large scaled with a dimension in the range of several millimeters and consist of a periodic reproducible structure. A minimum process duration of 6.3 min is achieved by an implemented nonstop single-line single-pass fabrication process and allows to write several identical specimens with different pore sizes from 10 µm up to 90 µm suitable for cell adhesion studies in a reasonable amount of time. OrmoComp®, an organic-inorganic hybrid polymer, is chosen as base material for the structures. Human dermal fibroblasts are directly seeded on scaffolds after several post-processing steps to ensure the extraction of toxic residues. Cell adhesion, proliferation, and survival are examined after three, six, and nine days of culture, respectively. Cell growth is compared depending on the different pore sizes of the scaffolds. Due to the horizontal and vertical cell growth observed on and inside the structures, we demonstrate that large scaffolds prepared from OrmoComp® qualify for three-dimensional cell adhesion and growth without support of an additional protein coating. [ABSTRACT FROM AUTHOR]

Abstract: Controlled synthesis of high‐molecular weight (MW) organic–inorganic hybrid polymers based on polyhedral oligomeric silsesquioxane (POSS) monomers has previously proved difficult to achieve by reversible‐deactivation radical polymerization methods. Here, this problem is tackled by employing a rarely used combination of Cu(0) catalysis and nonpolar solvents to polymerize a POSS‐methacrylate monomer, i BuPOSSMA. It is revealed that chain transfer to solvent plays a dominant role in this system as only benzene and not toluene allows for synthesis of low dispersity, ultrahigh MW products (up to 3 500 000). Importantly, the process is characterized by very low amounts (units of ppm) of copper released into the polymerization mixture, leading to products with no discoloration. Finally, benzene use is also shown to be beneficial for copper bromide–catalyzed polymerization of i BuPOSSMA, affording polymers with moderate MWs and extremely low dispersities (down to 1.06). [ABSTRACT FROM AUTHOR]

Siloxane-based polymer was synthesized through hydrosilylation of the 1,3,5,7-tetramethylcyclotetrasiloxane (TMCS) and 1,3-divinyltetramethylsiloxane (DTMS). Controlling the hydrosilylation reaction by varying the feeding ratio with the total monomer concentration, chemically-soluble siloxane-based polymer was obtained, which allowed film preparation as well as further incorporation of functional groups through the hydrosilylation reaction. The incorporation of 9-vinylanthracene was succesfully carried out by reacting Si-H groups of the TMCS−DTMS polymer with the vinyl-terminated anthracene derivative. Structural and thermal properties of the polymer were evaluated using NMR, GPC, FT−IR and flourecence spectroscopy. [ABSTRACT FROM AUTHOR]

Abstract: A ferric chloride–polyacrylamide inorganic–organic hybrid polymer has been synthesized using a ferric chloride/polyacrylamide ratio of 1:1 via free radical solution polymerization. A redox initiation system - (NH4)2S2O8 and NaHSO3 was used to initiate the polymerization at 50°C in aqueous medium. The ferric chloride–polyacrylamide hybrid polymer was characterized using Fourier transform infrared (FT-IR) spectrometer to determine their functional groups in the hybrid polymer chain. The FeCl3-PAM hybrid polymer was tested for flocculating activities on kaolin suspension and Terasil Red R dye wastewater. Parameters such as solution pH and FeCl3-PAM hybrid polymer dosage have been studied. One-way ANOVA shows that pH has a significant impact (p <0.05) in flocculating both kaolin suspension and Terasil Red R wastewater. The results show a minimum dosage of 2mg/L is able to remove more than 99% of turbidity in kaolin suspension at pH 2. FeCl3-PAM hybrid polymer also shows its capability in flocculating Terasil Red R dye wastewater. It is able to reduce 89% of COD and 99% of colour at pH 5 using 500mg/L of dosage. [ABSTRACT FROM AUTHOR]

Abstract: Inorganic–organic hybrid polymers were prepared by co-polymerization of styrene or methyl methacrylate in the presence of small proportions of the cluster Zr4O2(methacrylate)12. The thermal properties of the hybrid polymers were improved by the cluster-crosslinking. Variation of the reaction conditions had little influence on the thermal properties, although the gelation times were clearly influenced. The cluster-crosslinks were completely and selectively degraded by means of acetylacetone. This allowed the unique possibility of determining the number average molecular weights and polydispersities of the organic polymers which were initially interconnected by the clusters. [Copyright &y& Elsevier]

Abstract: Inorganic–organic hybrid materials were prepared by step-wise free radical polymerization of styrene in the presence of zirconium oxo clusters of the general compositions Zr6O4(OH)4(carboxylate)12 (carboxylate=5-norbornene-2-carboxylate or isobutyrate/methacrylate) and Zr12O8(OH)8(carboxylate)24 (carboxylate=acetate/propionate, vinylacetate, or acetate/methacrylate). Clusters with non-polymerizable ligands resulted in cluster/polystyrene blends which were soluble in toluene, whereas clusters with polymerizable ligands gave cluster-crosslinked, swellable polymers for which solvent uptake correlated with the functionality of the corresponding cluster. The onset temperatures of thermal decomposition and the glass transition temperatures of all cluster-containing polymers were higher than that of neat polystyrene, independent of whether the clusters were crosslinking or blended into the polymer. [Copyright &y& Elsevier]

A hybrid polymeric network was prepared through encapsulation of a new ruthenium complex within a poly(methylsilsequioxane) matrix. The Ru(III) complex was obtained using a tridentate his-amide derivate of the 2,6-pyridinedicarboxylic acid. The synthesis of the tridentate ligand and the entrapping procedure of the Ru(III) complex were presented. The polycondensation process of methyl triethoxysilane in the presence of the Ru(III) complex was studied in order to obtain information concerning the evolution of the gelation process. All products and intermediates were characterized using IR. UV-VIS. H-NMR spectral techniques, and elemental and thermogravimetric analyses. [ABSTRACT FROM AUTHOR]

Copper-mediated atom transfer radical polymerization (ATRP) of a protected silanol group-holding methacrylate, methacryloxypropyltrimethoxysilane (MOPS), was investigated. In a dry condition using carefully distilled solvent and monomer, the polymerization proceeded in a living fashion providing a low-polydispersity polymer with a predicted molecular weight. The ATRP in conjunction with the sequential monomer addition of methyl methacrylate (MMA) and MOPS afforded a block copolymer of the type PMMA-b-poly(MMA-r-MOPS). The heat treatment of a solution of the block copolymer in the presence of a catalytic amount of ammonia gave a polymeric core-shell nanoparticle with a shell of PMMA moieties and a core of the poly(MMA-r-MOPS) blocks cross-linked via the condensation of the trimethoxysilane groups of the MOPS moieties. [Copyright &y& Elsevier]

It is known that activation of P(2-VP) and P(4-VP) macromolecules by allyl derivatives of Me (Cr, W) or by metal-organic compounds of Li or Mg leads to formation of activity centers giving possibility for further growth of macromolecules due to side chains growth. It was shown by the authors, that activity of 4-VP groups is greater than that of 2-VP ones. We believe that varying the ratio between 2- and 4-VP in 2-4-VP copolymer it is possible to vary the number of activity centers in copolymer macromolecule and thus to regulate the number of side chains of this macromolecule. P(2-4-VP) copolymers with different content of 2- and 4-VP and also P(2-VP) and P(4-VP) samples were synthesized by free-radical polymerization under the same conditions and used as a core in formation of hybrid macromolecules with tributyl acrilate side chains. Data obtained show that following to this approach we get macromolecules with different architecture. Analysis of polymers and copolymers was carried out by molecular hydrodynamic methods (sedimentation analysis, translational diffusion, viscometry), MTA, NMR. [ABSTRACT FROM AUTHOR]